Chloro- and bromo-derivatives of 2-aminonaphthalene-1-sulphonic acid and process of preparing them



Patented Mar. 26, 1 935 I PATENT; OFFICE CHDORO- AND BROMO-DERIVATIVES"*OF.

2 AMINONAPHTHALENEEIF' 1, :SULPHONIGJ' '1 ACID AND PROCESS OF BREP RINGTHEM ManLange, Erankfort-on tl e-Main,and'i-Theo 'f dorjJacobs,"Wiesbaden;Germany,assignors to General Aniline Works, Inc., New York, N. Y.,

a corporation of Delaware" 'j' No Drawing." Ap plicationfJune 1932', Serial],

T' IN $17,042. In GermanyJune'H, 1931 9' Claims. ,(01. 260-129) 1' The present invention relates to newpchloroand promoderivatives. fj2 -aminonaphthalene e u hon qa nd t a p qc i pr r n them; more particularly; it relates to compounds 1 cf-the following general formula:,

wherein Y represents a sulphonic acidpgroup or a sulphonieacidisalt group and X'means that thenucleus Rj'contains a chloro or memo-atom. 'Wehave found "that the productsmayfeasily be prepared by replacing in a compound of the followingformula: HQ

wherein Y represents a sulphonic-acid group or a sulphonic acid salt group and X means that the nucleus R contains a chloroor'bromo-atom, the hydroxy group by the amino group according to one of the known methods using aqueous am- UO monia and an alkali sulphite. This process may preferably be carried out by heating in a closed vessel at a temperature of about 100 C. to about 200 C., advantageously at a temperature of 130 C. to 170 C., the hydroxycompounds of the above formula, with aqueous ammonia of strength in the presence of asulphite, preferably in the presence of ammonium sulphite.

This result was surprising since it could not be foreseen whether the halogen atom would remain in the molecule. In view of the conditions of the reaction it was to be expected that the halogen atom would be split off or replaced by the NH?- residue.

The halogen derivatives of the Z-hydroxynaphrials, may, for instance, be obtainedby transforming halogenated z-hydroxynaphthalenes into derivatives sulphonated in l-position, according to the process as described in Chemical.

thalene-l-sulphonic acid, used as starting mate- 1) 31 parts of technical, sodium salt or echloro-Z-hydroxynaphthalene-hsulphonic acid (obtainable, for instance, by treating 6chl01o-'-2- naphthol with sulphuric acid or chlorcsulphonic acid according to the aforesaidstatementsiinthe literature)- w-hich correspond with 28 partsof a pureproduct, are heated infa; closed .vessel fer about 30 hours at about 150 C, with 30 parts'of aqueous ammonia of 25% strength, 12 pfir its'of ammoniumsulphite, and 30'part's of waterp The reaction product is .takenupj in water, the ammonia'; is. distilled off the solution, ;if; necessary, is freed-fromimpurities by filtration and the new product is precipitated from ethefiltrate by addition of sodium chloride The sodiurn;salt;;o 'G chloro z-aminonaphthalene 1 sulphenic acid dissolves in-cold water in the ratio of 1:30; It crystallizes from alarge quantity of alcchol in the -forrn of white, brilliant leaflets,- Byaddif tion'of, mineralacid tothe .aqueoussolution of the sodiumsalt, the .free acid precipitates-in the form of white flakes whichappear under the mioroscope as thin'needles, The acid'rnelts a t,;a very high temperature with decomposition, it is I difiicultly soluble in water and yields a yellowish, difiicultly soluble diazo-compound. I

(2) 156 parts of technicalsodium salt, ofv 7- chloro-Z -hydroxynaphthalene- 1 -sulphonic acid,

corresponding with 140 parts of a pure product, are treated with 200 parts of aqueous ammonia of 25% strength, 60 parts of'ammonium sulphite and 100 parts of Water as indicated in Example (3) 170 parts of technical sodium salt of 7- bromo-z-hydroxynaphthalene-l-sulphonic acid, containing 163 parts of a pure product, are treated with 200 parts of ammoniaof 25% strength,' 50 parts of ammonium sulphite and 150 partsof water as indicated in Example 1. There is thus obtained 7-bromo-2-aminonaphthalene -'1 sulphonic acid. Its sodium'salt dissolves in cold. waterin the ratio of 1:20. Its other properties and those of the free acid correspond 'approximately with those of the compounds described in salts the free acids, the ammonia salts .of the halogenated amino-sulphonic acids are obtained.

We claim:

' ence or ammonium sulphitef I *1, The process which comprisesreplacing in a compound of the following formula:

wherein Y represents a sulphonic acid group or a sulphonic acid alkali metal salt group-{and X p -means that the nucleus Rcontains a ehloro-' or i 7 bromo-atom, the hydroxy group by the amino group using aqueous am noniaand'ammoniumj I w 1 ,sulphonic acid alkali metal salt group and X n meansthat the nucleus R contains apchloroor sulphite. 7 .7 V 1 2. The process which comprises heating'ina closed vessel at a temperature of about 100" C.

I to about 200" C. a compound of thefiollowing' formula: r

' 4; The process which comprisesheating awherein Y'represents a sulphonic aci'dgroup or a sulphonic acid alkali metal salt group and X j meansrthat the nucleus R contains a chlor o-. -or

bromo-atom, with aqueous ammonia of 25% strength in the presence of ammonium sulphite.

3-. The process which'c'omprises heating in a closedvessel at a temperature of; about 150" C. for about30 hours thesodium salt of 6-jchloro-2 hy'droxynaphthalene l sulphonicacid "with aqueous ammonia/of strength in'the' presence of ammonium sulphite; i

clcsedvessel at a temperature of about 150 C;

for about hours the sodium salt of 7-chloro-2- hydroxynaphthalene 1- 'sulphonic aqueous ammonia of 25% strerigthjihthepres- 5. The process which comprises heating in a closed vessel at atemperature of about- C.

acid with aqueous ammonia or 25% strength in the presence of ammonium sulphite, H V p 6. The compounds of the following general formula: 7 7 V wherein'Y represents'afsulphonic acid group or a bromo atom. I i 4 x '7. a 6 chloro-2 aminonaphthalene l-sulphonic acid, separating from the aqueous' solution oithe sodium salt, by'additionof mineral acid, in the form of white flakes which appear under the microscope as thin needles,, m'elting at. a very I high temperature with decomposition, being difficultly soluble inwater and yielding a "yellowish, diflicultly soluble diam-com o s 8. 7 chloro-2-aminonaphthalene-1 1 acid, separating from .the aqueous solution of I the sodium salt, by addition of mineral acid, in j thef or'm of white flakes which appear under the microscope as thin sneedlesgmelting ata'very high temperature with decomposition, being dif r ficultly soluble in water and yielding a yellowish, diflicultly soluble diazo compound. 5

' 9. "'15jbromo-2-aminonaphthalene 1 -sulph'onie acid, separating fromthe."aqueous solution of the sodium salt, byaddition of mineral acid, in the formof white flakes which appear under the microscope as thin needles,- melting: at' agvery high temperature with decomposition, being difficultly soluble in water and yielding a yellow ish, diflicultly soluble ,diaz'o-compound. 

